Field of The Invention
The present invention relates to a hydrophilic composite porous membrane, a method of producing the same and a plasma separator in which the hydrophilic composite porous membrane is accommodated. More particularly, the present invention is concerned with a hydrophilic composite porous membrane comprising microfibril bundles, knotted portions cross-connected to the bundles and a specific copolymer coat formed substantially on the overall surface of the bundles and knotted portions. The membrane may take various forms, for example a hollow fiber form, and exhibits an excellent water or solute permeability without being subjected to any pretreatment and has excellent mechanical properties in the wet state as well as in the dry state. The present membrane advantageously does not contain any undesirable materials, such as a surfactant, a water-soluble polymer, etc., which had inevitably been used in rendering hydrophobic membranes hydrophilic according to the conventional methods. The present invention is also concerned with an effective method of producing the above-mentioned membrane in which a copolymer solution is applied to a polyolefin membranous matrix, followed by drying. Moreover, the present invention is concerned with a plasma separator containing the above-mentioned advantageous membrane.